Recent safety considerations require that molded case circuit breakers having rear mounted line terminal connections be prevented from removal from an electrical panel box by the application of an ordinary pulling force. When the breaker switch is in the open position, and the line terminals are connected to the breaker, the energized breaker contacts can become a source of potential harm to an operator when the breaker is disengaged from the panel. An early attempt to prevent removal of a circuit breaker from a panel board is described in U.S. Pat. No. 3,111,354, H. J. Hammerly et al, wherein a U-shaped locking member is employed to retain the breaker within the panel against manually exerted removal force. In order to remove the breaker from the panel, a specially designed removing tool must be employed. U.S. Pat. No. 3,093,773, T. M. Cole, discloses a spring clip arrangement wherein the spring clip is attached to a circuit protective device for interlocking engagement with the panel box pan hook. To remove the device from the panel board, the panel board must be disassembled in order to provide access to the clip for disengaging the clip from the pan hook.
The purpose of this invention is to describe means for retaining a circuit breaker within a panel board against the ordinary manual forces applied to remove the breaker from the panel board. The circuit breaker can be removed by the application of an ordinary tool, such as a screwdriver, for example.